That is quite horrible. If having the second kid is by now unavoidable, you should at least have an IUD inserted, without his knowledge, at 6 weeks postpartum. Modern IUDs provide about 99% protection against another pregnancy without the need for cooperation from the man. I wonder why your OB-GYN who delivered the first baby did not discuss contraception options with you at the first postpartum visit or even before the birth. Doing so is a standard of care.